KCNA4 Gene SNP and OV2max Response to Endurance Training

0709 The K+ voltage-gated channel of the shaker-related subfamily member 4 (KCNA4) gene (11p14), encodes for the K+ transient current (ito) channel which modulates the cardiac cell action potential. PURPOSE: We tested the hypothesis of an association between a C\T transition in the KCNA4 gene and OV2max response (Δ = Pre – Post OV2max) to 20-wk endurance-training (ET). METHODS: Pre- and Post-ET OV2max was measured by progressive exercise tests on a cycle ergometer. The polymorphism was detected by PCR and digestion with Tsp45I in 759 DNA samples from the HERITAGE Family Study (Blacks = 267 and Whites = 492). RESULTS: ÷2: ÷ indicated Hardy- Weinberg equilibrium and that the observed genotype frequencies were not different between races or genders. Δ values for OV2max adjusted for age, gender, race, Pre-ET OV2max, and body mass were characterized by genotype differences (P = 0.045). TT carriers had significantly lower ΔOV2max (396.4 ± 25 mL/min) than both CC (423.6 ± 25 mL/min) and CT carriers (435.6 ± 21 mL/min). CONCLUSIONS: The C/T transition at the KCNA4 locus or a gene in strong linkage disequilibrium is associated with ΔOV2max in Blacks and Whites. Supported by NHLBI of NIH, RCMI-CRC #1P20RR11126, and RCMI #G12RR03051.